System and method for controlling a level crossing of a railway track

Abstract

A system controls a level crossing of a railway track installation. The railway track installation includes at least one track. The system includes at least two magnetometers associated with the at least one track and placed at corners of a crossing area between the at least one track and a road. The system also includes a level crossing control unit configured for receiving data from the magnetometers. Each magnetometer is arranged to detect a respective magnetic field vector of the earth's magnetic field and to send data representative of the magnetic field vector to the control unit. The control unit is configured to elaborate the data to detect changes in the magnetic field vectors due to the presence of a train in the crossing area and to control the level crossing as a function of the detected changes.

Claims

1. A system for controlling a level crossing of a railway track installation, the railway track installation comprising at least one track, the system comprising: at least two magnetometers associated with the at least one track and placed at corners of a crossing area between the at least one track and a road; a level crossing control unit configured for receiving data from the magnetometers; wherein each magnetometer is arranged to detect a respective magnetic field vector of the earth's magnetic field and to send data representative of said magnetic field vector to the control unit, the control unit being configured to elaborate said data to detect changes in the magnetic field vectors due to the presence of a train in the crossing area and to control the level crossing as a function of said detected changes.

2. The system of claim 1, wherein the control unit is arranged to control level crossing warning devices associated to the crossing area.

3. The system according to claim 1, wherein said magnetometers are placed near the rails of the at least one railway track or buried in the ground or mounted on or in ties of the at least one railway track.

4. The system of claim 1, wherein said data representative of magnetic field vector are sent by each magnetometer to the control unit through a safety communication protocol.

5. The system of claim 1, wherein the control unit is arranged to detect a strong shift in the magnetic field vector from a reference when the train passes near the magnetometers.

6. The system of claim 1, further including calibrated magnetic field sources associated to a respective magnetometer and configured to verify the sensitivity of each magnetometer to ensure the correct operation of each magnetometer.

7. The system of claim 6, wherein the calibrated magnetic field sources are arranged to generate corresponding test magnetic vectors to be detected by the magnetometers, so as to verify that corresponding integrity test data are not impacted by other external magnetic fields.

8. The system of claim 6, wherein said calibrated magnetic field sources are controlled energy sources including an inductor.

9. The system of claim 6, wherein the calibrated magnetic field sources are packaged with the respective magnetometer and positioned with a predetermined orientation.

10. A method for controlling a level crossing of a railway track installation, the railway track installation comprising at least one track, the method comprising the steps of: placing the at least two magnetometers of the system according to any of the preceding claims at corners of a crossing area between the at least one track and a road; detecting, through said magnetometers, respective vectors of the earth's magnetic field; sending data representative of said vectors to the control unit; detecting, through the control unit, changes in the magnetic field vectors so as to determine if a train is present in the crossing area, controlling, through the control unit, the level crossing as a function of said changes.

11. The method of claim 10, further comprising providing a calibrated magnetic field source associated to each magnetometer and arranged to generate a respective test magnetic vector to be detected by the associated magnetometer, to be used to verify the sensitivity of the magnetometer to ensure its correct operation.

12. The method of claim 11, further comprising dynamically modifying the calibrated magnetic field source so as to obtain different test magnetic vectors, to be used to verify that corresponding integrity test data are not impacted by an external magnetic field.

13. The method of claim 12, further comprising sending the representative data of the integrity tests performed through the calibrated magnetic field source from the magnetometer to the control unit, which in turn verifies if the integrity tests have failed, thus assuming that the crossing area is occupied.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) Further characteristics and advantages of the present invention will become apparent from the following description, provided merely by way of a non-limiting example, with reference to the enclosed drawings, in which:

(2) FIG. 1 is a schematic view of a system for controlling a level crossing of a railway track according to the present invention; and

(3) FIG. 2 is a block diagram of the steps of a method for controlling a level crossing of a railway track according to the present invention.

DETAILED DESCRIPTION

(4) FIG. 1 shows a schematic view of a system for controlling a level crossing of a railway track according to the present invention.

(5) A railway track 2 comprising two paths 2a crosses a road 4 in a crossing area 6. A train 8 is on one of said two paths 2a.

(6) The system of the present invention comprises at least two magnetometers 10 per path 2a, placed at the corners of the crossing area 6 where the presence of the train 8 must be detected.

(7) These magnetometers 10 are alternatively placed near the rails of the railway tracks 2a of the two paths, buried in the ground, mounted on or in ties, which are known wooden or concrete supports that lie the railway track underneath and that are mounted perpendicular to the rails, etc. The magnetometers 10 can have a wired or wireless connection to a level crossing control unit 12, the so called xWIU (Crossing Wayside Interface Unit), which is arranged to control, preferably in a wireless manner, level crossing warning devices 14 per se known, such as gates, lights, bells, etc. in order to manage all the level crossing activation functions.

(8) Each magnetometer 10 is arranged to detect a respective vector 16 of the earth's magnetic field, along three axes, in particular by measuring amplitude and orientation angle of said vector 16. Data representative of each earth's magnetic field vector 16 are sent by each magnetometer 10 to the control unit 12 through a safety communication protocol per se known, preferably a serial/Ethernet protocol.

(9) When the train 8 occupies the crossing area 6, the earth's magnetic field is reoriented as it is attracted by the large metallic structures of the rail cars of the train 8, such as the engine, the car body, the wheels, etc.

(10) A software algorithm per se known performed by the control unit 12 analyzes the data received by the magnetometers 10 and detects changes in the vectors 16 of the earth's magnetic field, thus determining if the train 8 is present on the railway tracks 2a. In particular, a strong shift in the magnetic field vector 16 from a reference is measured when the train 8 passes near the magnetometers 10. As an example, the earth's magnetic field along the Z axis points inward towards the earth's surface at about 500 mG. As the train 8 comes into proximity of the magnetometer 10, it attracts the earth's magnetic field towards the rail cars (i.e. outward from the earth's surface) at a different magnitude and direction, for example about 100 mG. This change, in magnitude and direction along the Z axis, of the earth's magnetic field vector 16 is sensed by the magnetometer 10.

(11) If the earth's magnetic field vector 16 of any one of the magnetometers 10 deviates from a predetermined static magnitude and/or orientation of the earth's natural magnetic field, the crossing area 6 is assumed to be occupied. Conversely, the earth's magnetic field vector 16 of all the magnetometers 10 must be within an expected range to determine the crossing area 6 as unoccupied.

(12) If the crossing area 6 is determined as occupied, the control unit 12 controls accordingly, in a manner known per se, the level crossing warning devices 14, so as to prevent any crossing of the level crossing area 6 by vehicles or pedestrians moving along the road 4.

(13) In addition to the above, in order to protect the system of the present invention against magnetometers' failure modes, for example loss or changes in sensitivity, known calibrated magnetic field sources 18, such as controlled energy sources advantageously including an inductor, are respectively associated to the magnetometers 10 and used to independently verify the sensitivity and accuracy of each magnetometer 10, to ensure the correct operation.

(14) Advantageously, the calibrated magnetic field sources 18 are packaged with the respective magnetometer 10 and positioned with a predetermined orientation.

(15) Through the design of said calibrated magnetic field sources 18 it is possible to control the strength and orientation of a test magnetic field generated by the respective source 18, in particular by controlling the inductance, the current and the mounting direction of these sources 18.

(16) Each source 18 produces a corresponding test magnetic vector.

(17) If a magnetometer 10 does not identify exactly as expected its test magnetic vector, the crossing area 6 is considered as occupied. In fact, the test magnetic vector generated by each source 18 is known a priori because it is generated in a predetermined manner by acting on the source 18 itself, therefore, if the magnetometer 10 associated to each source 18 does not measure the parameters of the test magnetic vector as generated, a failure is determined for the magnetometer 10 and the crossing area 6 is considered as occupied for safety precautions.

(18) These calibrated magnetic field sources 18 are further arranged to be dynamically modified/encoded by changing for example the frequency or phase amplitude, so as to generate different test magnetic vectors to be detected by the associated magnetometer 10, thus verifying that corresponding integrity test data are not impacted by other external magnetic fields. This also allows the integrity tests to be performed periodically, independently of whether or not the train 8 is present in the crossing area 6.

(19) The magnetometer sensitivity and output correctness can be therefore verified each time the test magnetic field is enabled, because each magnetometer 10 is periodically tested using said test magnetic field to ensure that its data are correct and that it is properly functioning.

(20) The data representative of these periodic integrity tests are sent from each magnetometer 10 to the control unit 12 which verifies if the integrity tests have failed, thus assuming that the crossing area 6 is occupied, as above indicated.

(21) All of the features of the system above described provide a failsafe design that is capable of replacing standard island track circuits while avoiding the use of wires attached to the railway tracks 2a or additional equipment.

(22) In the following a method for controlling a level crossing island will be disclosed with reference to FIG. 2, which shows a block diagram of the steps to be performed.

(23) The method is performed with reference to a system of the type above disclosed.

(24) In an initial step 100 at least two magnetometers 10 per path 2a are placed at the corners of a crossing area 6.

(25) Then, at step 102, each magnetometer 10 detects a vector 16 of the earth's magnetic field along three axes, in particular it detects amplitude and orientation angle of said vector 16.

(26) In a further step 104, data representative of said vectors 16 are sent by the magnetometers 10 to a control unit 12 through a safety communication protocol per se known.

(27) Finally, in a step 106, the control unit 12 detects changes in the vectors 16 of the earth's magnetic field, thus determining that a train 8 is present in the level crossing area 6.

(28) In a preferred embodiment of the invention, the method further comprises the step of providing 108 calibrated magnetic field sources 18 associated to each respective magnetometer 10 and arranged to generate a respective test magnetic vector. The test magnetic vector is detected by the magnetometer 10 to verify the sensitivity of the magnetometer 10 itself and to ensure its correct operation.

(29) In a further step 110 these calibrated magnetic field sources 18 are dynamically modified/encoded so as to generate different test magnetic vectors to be detected by the magnetometers 10, in order to verify that corresponding integrity test data are not impacted by an external magnetic field.

(30) In a final step 112, the data representative of these periodic integrity tests are sent from each magnetometer 10 to the control unit 12 which, in a step 114, verifies if the integrity tests have failed, thus assuming that the crossing area 6 is occupied.

(31) Clearly, the principle of the invention remaining the same, the embodiments and the details of production can be varied considerably from what has been described and illustrated purely by way of non-limiting example, without departing from the scope of protection of the present invention as defined by the attached claims.